As advanced countries actively recently push reinforcement of fuel consumption regulations and development and spread of an environmentally friendly vehicle, demand for a plug-in hybrid electric vehicle/an electric vehicle (PHEV/EV) has been rapidly increased. However, due to inconvenience caused by a long charging time and a short driving distance and a high cost, trust of consumers for the environmentally friendly vehicle is not high till now. Therefore, technology of increasing a driving distance of the environmentally friendly vehicle by mounting a large capacity battery in the environmentally friendly vehicle has been developed.
However, a capacity of a battery charger also needs to be increased in order to shorten a charging time increased due to an increase in a battery capacity, and when the capacity of the battery charger is increased, a size and a cost of the battery charger are also increased in proportion to the capacity.
Since the environmentally friendly vehicle has a problem such as a narrow internal space and a cost higher than that of a general internal combustion engine vehicle, it has become important to decrease the size and the cost of the battery charger while increasing the capacity of the battery charger.
In the case of a conventional 11 kW-level low speed charger, due to a large capacity, converters of a power factor corrector (PFC) stage and a direct current (DC)-DC stage are generally configured in two to three parallel structures. As the number of converters is increased, the number of microcomputers for controlling the converters is increased, and a circuit becomes complicated.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.